1. Field of the Invention
The invention relates to a toilet system with a toilet pan, which can be flushed by a flushing arrangement, having a conduit which is connected to the toilet pan and leads to a waste-disposal conduit, having means for transporting a suction-extraction substance from the toilet pan into the conduit and into the waste-disposal conduit, the means having, in the conduit, two valves and, between the latter, a pressure chamber in which it is possible to produce a negative pressure, for the suction extraction of the substance from the toilet pan, and a positive pressure, for transporting the substance, once extracted by suction, into the waste-disposal conduit.
2. Description of the Related Art
Up until now, toilet systems in which the suction-extraction substance is extracted by means of a vacuum have been known, in particular, in vehicles, for example in railroad cars and RVs. For example, WO 92/18713 discloses a toilet system in which an arrangement for producing negative pressure has an intermediate tank and a collecting tank. The abovementioned arrangement evacuates the intermediate tank in order to produce negative pressure, with the result that, with a valve in a conduit being open, the substance is taken into the intermediate tank. Collecting tanks require a large amount of space and have to be emptied. They are not desirable for domestic use.
EP 0 887 478 discloses a toilet system in which a tank is likewise provided. A diaphragm pump is used to produce a partial vacuum in the tank, this resulting in a suction-extraction action.
EP 0 806 527 discloses a flushing arrangement which has a hollow, cup-like closure element. The closure element interacts with an inlet opening and an outlet opening, which are both open or closed in each case.
Toilet systems with a collecting tank in each case have additionally been disclosed by EP 0 704 372 and EP 1 022 399.
EP 0 763 633 A1 discloses a vacuum toilet which, in the discharge conduit, has a pressure chamber between two valves. By virtue of the negative pressure in this chamber, when a valve on the inlet side is opened, suction-extraction substance is sucked from the toilet pan, through the discharge conduit into this chamber. Once the two valves have been switched over, pressure forces the substance from the chamber into a further conduit. An ejector pump which is operated with compressed air is provided in order to evacuate the chamber. A folding bellows in the pressure chamber forms a flexible membrane and serves as a sealing means, and is intended to prevent foul air from passing outward out of the discharge conduit. The production of the negative pressure causes a spring to be stressed, the spring building up a pressure when relieved of stressing. The problem with this toilet system is that sealing the chamber by means of a flexible membrane involves high outlay and is fault-prone. In order to build up a negative pressure, an ejector pump requires a comparatively long period of time. In addition, the pressure which can be achieved in order to expel the substance from the chamber is very limited. This toilet system is not likely to prove successful in practice.
The object of the invention is to provide a toilet system of the abovementioned type which, with low water consumption, is functionally reliable and durable.